Jack



sEsTAvAiLAeLE com' iatente'd May 18,v 1926.

UNITED s'rnres PATENT orFr-'cE.-;,

n -PHILIP E. WALL, F MILFORD, MASSACHUSETTS, ASSIGNOR T0 F. WrHANN COM- rm..or n nonn, no, snuse'rrs, A CORPORATION or mssaonusmrs.

Jeux,

Application tied July 7,1825. Serial No. 41,980.

The present inventionv relates 11o an improvement 'in jocks.

.The object of the invention is to reorganize and improve the construetim of jacks, and more. particularly -screv'v jar-.les The invention consists in the jack hereinafter v of the outer screw 13 by means of the spring.

described and particularly defini-:i the claims.

In the drawings illustrating the preferred forni of the. invention, `Fig. 1 is a sec-.tions eleifstioix-o s jerhgfig. 2 is a. plan; Fig. 3 'is' e section-teken.- -on the line 3-3, Fig. 1; and Fig. 4 is'a sectional elevation of the javi." head.-

.The illustrated embodiment. of the in#` Ventron is described as follows: The gael-L comprises a. body 10 hir-:ing a foot 11 -in-' tegral therewith. The body of the joel: cylindrical in form at the. bottom, and en larged at the top to receive two revel gears by which the jack is operated. The' pillar 12 of cy indrical forni extends upward from the foot or. bese, and receives the screws. ,There are two of these screws, an outer screwr 13, and an inner screw 14, the. former being' screwthieaded through the hub of the bevel inion 15, andthe letter being screwthrea ed through the 4head 16 of the outer screw 13. The outer screw 13 is provided with 'a longitudinal groove. 1?, extending from end to end thereof. This groove receives a. roll 18 supported ir. the housing of the pillar and pressed into the. groove 1? 19, the spring taking against the cotter pin 20 which holds it in place. The pressure of the' spring 19 on the roll 1S operates to hold the outer screw 13 from turning except when its tendenc to turn is great enough to push the rolly of the groove 17. A driving pinion 21 meshing @Vith the driven pinion 15, is used to roiatethe driven or lifting pinion 15. It is pinned on the shaft 22, which is supported in bearings 23, 24:, of the lrousing at the top of the pillar l2.

turn rotates the driven or lifting pinion 15, which operates either to directly lir't the outer screw 13 While the latter is held vin place by the. detent 18, or it turns the outer screw and thereby causes the inner screw to lie raised.

The driving shaft 22 is provided with a head '-25. to which pinned the fork 26 or detent 18 out By turningthe shaft 22, the driving pinion 21 is rotated, and it in 26 is formed on' the 'end of asle'eve 2 8, which receives .the de teht 29 adaptedfto engage the recess'() in the head 25,.bcing p ressd. in 'a direction-to engage such recess .by trie spring 31, 'received in the sleeve :is .shown ed to receive the head 33 of an opertlpg shaft fworkdgby 'crankhandle in;

lusual way.'

The driven oir-lifting pinion 15 is'prefexgeblymade -of bronze" and supportedongits' t9 under side by a ball bearing-35. Theuppgij by mea-ns ofthe riveted pin 27. The

l at its outer end with a square hole32, ,1 6

end ofith pinion'hub is reduced ,in ,at

and received in a hole' in the`cover plate .'-T. secured to thetop of the housing 'by ineens of the screws 38. This affords-al good support for the driven or lifting pinion and holds it in proper position with in tion to. the screws and the driving pinion',-

and as. weil supports the jack screws in eorrca-t position in the jack. f

The top 'o f the jack is 'provided with a heini 39 with a rough'ened surface', adapted to cause it to engage and -hold almOStjny sort of a surface of the body to be liftedby the jack. incidentally, this operates to lock the inner screw from rotat1on,.'which`1,is

necessary in order' tosecure. the desired .operation of the. nek.

The upper surface of thehead 39 is ro. vided with. V-shaped 'grooves arrange at right angles to each other, thus forming pyramidal projections,fand the center of the upper surface of the head i's cupped so that when the head engages a convex body, it tends toseat itself securely on the head ofl the inner screw 14.

The housing 40, supportedby the illar,

completely encloses the driving and rivenpinions, and affords an oil well int vhich the lower edge of the driving pinion -may dip so that it may continuous y carry oil to ioo the teeth of the upperpinion. This oil well is .formed by the outer portion of the housing 40 and the inner web 41 wheh extends upward from the :,ottoin ci to the. floor 42 of the housing for the driven pinion. This floor is spot-facedv to receive the lower raceway of the ball beeriug, the upper .raceway of which rests directly upon the balls and comes directlyA engagement outer housing Y o n its upper side with the driven or lifting pinion.

Thecover plate 37 serves vthe double funetion of closing the housin f and all'ording a hearing to contribute to t ie support of the driven or lifting pinion.

It will he observed-that without the detent and without holding the inner screw stationary, both the/screws and the driven pinion o turn together'. If, however, the detenthe u held freni rotation until the end of the thread groove of-theoutside serewll is enga fed by the end of the thread of the driven or' 'fting pinion 15. Then further rotation of the driving pinion operates to turn the lo outer-sferen', and the inner screw, being held from rotation by engagement of its head with the object or thing to be lifted, rises from the inner screw and further lifts `the Aweight or thing resting upon it. The latter is headed at the bottom so that it can be turnedonly to a certain determined hei frl|t. In lowering the jack, the outer screwv irst descends until the'upper end of the thread of the outer screw engages the lifting or driving pinion 15, whereupon the driving pinion picks up the outer screw 13 and rotutes it, andthe'inner screw, being held fronf rotation as described, is then lowered hy the turning ofthe outer screw thereon.

1. A jrek comprising a. frame, two screwff, an inner sorew and an outer screw, the inner screw being-threaded inside of the outer screw, a driving pinion threaded on the outside of the outer screw, the outer screw heing provided with a longitudinal groove in the latter4 from rotation except when i excessive pressure la exerted thereon, and

.the detent into the groove in the outer screw l BEST AVAlLABLE COP-Y its exterior, a sprin pressedV detent engaing suehgroove in t e outer screw and hol ing it from rotation at times.

2. A jack having, in combination, a frame a screw, a nut enga fing the screw, a j screw serewthreade inside the first fsorew, the outer screw bein f provided with nlongilf 'f tudinal groove, a ey indrical roll adapted' to j engage the groove in the outerscrew andjto yielding means for holding the roll ii-detent m position. l V 4 3. A doublelserew jack having, in eomhi-v 5r nation, an outer screw provided with an ex ternal and an interniil thread, a nut for eni gaging the 'external thread, a second screw engagm the internal thread, the external thread ing provided with stops at both 00 ends and with a longitudinal groove, a frame-work for supporting theparts irovided with a detent recess, a cylindriea detent :supported in the detent recess, a 'spring backing up the detent and received in the dees tent rwess-z, and means for holding it therem.

4. A- douhle screw jack having, in tannini-- nation, an outer screw provided with inter-rf, nal and external threads,`'a nut-'engaging the outer thread, said outer thread' being p'rovided with a longitudinal'groove, a frame,

a detent-boss on the side of the frame, a detent recess in the hoes, a. eyglindrioal detent.J loosely mounted in the recess, a spring, and." means for holding it inthe rerzeas to presa j 'l 'i exec it when pressed-outwardly hy pressure v of t ie walls of the groove thereupon.

in testimony whereof I have signedfmy l0 naxneto this 'peciiieation. i

PHILII S. KIMISALL. 

